Apple 'stunned' to discover iPhone signal strength flaw

Apple 'stunned' to discover iPhone signal strength flaw

Summary: Responding to complaints about the iPhone 4 losing signal when held in a certain way, Apple has said all iPhone models misreport signal strength


Apple's iPhone handsets have been over-reporting signal strength since they were first launched, the company said in response to reports of the latest version of the smartphone losing signal when held in a certain way.

In a open letter on Friday to iPhone 4 users, Apple said it had been "stunned" to find that the formula it uses to calculate how many bars of signal strength to display "is totally wrong". The company said it had discovered this longstanding flaw — the first iPhone came out three years ago — when investigating reports of the iPhone 4 losing four or five bars of reception "when tightly held in a way which covers the black strip in the lower left corner of the metal band".

"Our formula, in many instances, mistakenly displays two more bars than it should for a given signal strength," the letter read. "For example, we sometimes display four bars when we should be displaying as few as two bars. Users observing a drop of several bars when they grip their iPhone in a certain way are most likely in an area with very weak signal strength, but they don't know it because we are erroneously displaying four or five bars.

"Their big drop in bars is because their high bars were never real in the first place."

Previously, Apple had explained the iPhone 4 reception problem by saying the issue was a "fact of life for every wireless phone". In Friday's letter, the company again said that gripping almost any mobile phone in certain ways will reduce its reception by one or more bars, but conceded that the iPhone 4 showed a "far bigger drop than normal".

"To fix this, we are adopting AT&T's recently recommended formula for calculating how many bars to display for a given signal strength," the company said. "The real signal strength remains the same, but the iPhone's bars will report it far more accurately, providing users a much better indication of the reception they will get in a given area. We are also making bars 1, 2 and 3 a bit taller so they will be easier to see."

A free software update that fixes this misreporting of signal strength will be pushed out to users of the iPhone 3G, 3GS and 4 within a few weeks, Apple said.

Apple added that "the iPhone 4's wireless performance is the best we have ever shipped" and signed off the letter with: "We hope you love the iPhone 4 as much as we do. Thank you for your patience and support."

ZDNet UK has asked Apple to explain the connection between the misreporting of signal strength and the iPhone 4's greater-than-normal signal drop-off when held in a certain way, but had received no answer at the time of writing.

The company is currently facing a class-action lawsuit in the US over the iPhone 4 signal issue.

Topics: Mobility, Smartphones

David Meyer

About David Meyer

David Meyer is a freelance technology journalist. He fell into journalism when he realised his musical career wouldn't pay the bills. David's main focus is on communications, as well as internet technologies, regulation and mobile devices.

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  • why has no-one pushed apple to come out on this on previous phones --- i know lots of people with iphones (including myself) that have problems of v poor/no service reception in low 3g/ 2g areas and being fobbed off by suppliers that it is unusual/not heard of and the fault is ours
    keep at it znet andf ;et the world know
    Perhaps we may see phones compared for their reception rather than only the fancy gadgets in the future --- we in rural areas can but hope
  • Sounds to me like a marketing scam from three years ago has come back to bite them in the arse, question is how many other mobile phone companies have also previously adopted this malignant method over that time.
  • Funny.. neither of my Nokias care how I hold them, they always work even where other makes have problems! :-)
  • How did they miss this.... Do you think the test manager still has a job?
  • @catmur - I've been an apple user since 1995... but i guess their marketing tricks are going way too far... I think the test manager..or engineer is either in a hot seat or burnt....
  • If this was Microsoft or Another cell phone manufacturer, there would be hell to pay. This is ridiculous you have a crazy expensive piece of hardware and this is the response: Ca said "question is how many other mobile phone companies have also previously adopted this malignant method over that time." Let's focus on the true issue; APPLE is behaving in a way that is unacceptable, get it fixed make reparations to their loyal customers and move on. A thank you and a software update are not enough. Fix the new model, refund the money ifthe user no longer wants the phone and replace. Any other company and we would be talking class action lawsuit.
  • I have heard a rumour (that's all it is) that, as real-world testing was done using cases to disguise the iPhone 4s as iPhone 3GSs (see the Gizmodo device as an example), the problem did not manifest itself at that point. Of course, Apple would have done a lot more testing than that, so there must be more to it...
    David Meyer